Drill bit



y 30, 1963 J. A. PURSER, SR 3,099,325

DRILL BIT Filed Oct. 30, 1961 2 sh t -s t 1 IN ENTOR. James A. rser,$r.

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ATTORNEYS July 30, 1963 A. PURSER, SR 3,099,325

DRILL BIT Filed Oct. 30, 1961 2 Sheets-Sheet 2 1 i l I I4 I5 5 l4 1 l l5 W1 [6 I I3 i I3 I3 INVENTOR F. James A. Purser,S|:

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ATTORNEYS United States Patent 3,099,325 DRILL BlT James A. Purser, Sr., 2213 N. 15th St, Grand Junction, (Zola. Filed Oct. 30, 1961, Ser. No. 148,445 6 Claims. (Cl. 175-412) This invention relates to a drill bit for drilling wells, and more particularly it relates to a rotary drill bit with removable blades having improved means for securing these blades in place.

In both exploration and production drilling economical and fast drilling operations demand a drill bit that can have its worn blades changed without lengthy shutdown periods. Also, a drill bit of this nature must have means to securely lock the blades in place.

Accordingly, it is a primary object of this invention to provide a drill bit having a plurality of demountable blades that can be quickly and easily locked in place.

It is a further object of this invention to provide a drill bit having improved means for supporting the demountable blades.

Another object of this invention is the provision of a drill bit having demountable blades which are constructed to assist in bracing each other in place to prevent their breakage.

A still further object of this invention is the provision of a rugged drill bit having a minimum of component parts which will give trouble-free service to the user thereof and which will be inexpensive to manufacture. These and other objects and advantages of the invention will become apparent from the following specifications and drawings wherein like numerals refer to similar parts throughout.

In the drawings:

RIG. 1 is a elevation of the drill bit showing the blades locked in place,

FIG. 2 is a bottom plan view of FIG. 1;

FIG. 3 is a section taken along the line 33 of FIG. 1;

FIG. 4 is a section taken along the line 4-4 of FIG. 1; and

FIG. 5 is an exploded view of the drill bit of this invention.

Basically, the drill bit includes a central body member which is attached to a drill rod, a plurality of demountable blades, and a sleeve having means thereon to cooperate With means on the body member and blades for securing the blades in place. 'In the embodiment of the invention shown for purposes of illustration the drill bit is seen to include three blades. Of course it will be realized that it is Within the scope of the invention to provide a drill bit having any convenient number of blades.

Referring to the drawings it Will be seen that the drill bit includes a tubular body member 10, a plurality of deniountable blades 11, and a sleeve 12. The hollow body member is a one-piece structure having on its upper portion a plurality of threads adapting it to be secured to a drill rod and having on its lower portion a plurality of equally spaced-apart, longitudinally extending, integral fingers 13. Extending integrally from the Wall of the body member at each of the fingers thereof are projections or shoulders 14 having an inclined face 15 at one end thereof. It will be observed that a portion of the finger 13 extends outwardly beyond the outer surface of the body member, and the upper part of this portion and the shoulder form an annular segment which serves, inter alia, as a stop or rest for the sleeve 12. A radial slot 16 is provided in the wall of the body member adjacent each finger. The base of this slot and the underside of the shoulder 14 form a seat for the blade 11. The fingers 13 are ribbed on their backside and they terminate in a reduced portion or tip 17.

3,099,325 Patented July 30, 1963 Each of the novel blades 11 of this invention has on its backside a number of ribs 18. The innermost ribs are cut away to provide the fiat portion 19, and an extension of this flat portion or groove 20 is provided between two of the ribs 18. The upper portion of the blade has inner and outer extending legs 21 and 22, respectively, and formed on the forward side of the blade is a projection 23 having an inclined face 24. The lower portion of the blades extend toward each other beneath the body member and they have on their forward side a laterally 'angularly projecting lug 25 adapted to abut the backside of the adjacent blade. 1 The sleeve 12 is axially slidable on the drill rod and body member 10, and it has a plurality of equally spaced, longitudinally extending ears 26. Each ear has an inclined side 27 and an arcuate side 28 joining the main portion of the sleeve 12 at a short side 29. This construction forms open spaces 30 between the ears.

The blades of the drill bit are quickly and securely mounted in place as follows: The generally vertically disposed blades 11 are radially mounted with respect to the body member 10 by being seated in the slots 16 with the inner legs 21 extending along the inner surface of the body member and the outer legs 22 extending along the outer surface of the shoulder 14. The flat front side of the fingers 13 will abut the flat portions 19 of the blades and the tips 17 will be received by the grooves 20. When the blades are fully in place the inclined face 15 on the shoulder 14 will be juxtaposed and coplanar with the inclined face 24 on the blade 11. At the same time the lug 25 will be in freely abutting contact with the backside of the adjacent blade as best seen in FIG. 2.

Next, the sleeve 12, which is slidably engageable with the body member 10, is dropped into position. :Each blade 1'1 and its corresponding finger 13 are received in the open space 30 and the upper side of the open space 30 rests on the top surface of the shoulder 14. The inclined side 27 of the ear 26 will abut the inclined faces 15 and 24 on the body member and blade, respectively, while the side 29 which is parallel to the side 27 will engage an inclined end of the shoulder 14 opposite the inclined face 15 thereof as best viewed in FIG. '1. This prevents the leeve 12 from rotating and consequently the ears 26 are prevented from backing off of the inclined faces 15 and 24. It will be readily seen that this construction securely locks the blades in place. They are prevented from lateral movement by the straddling engagement of the legs 21 and 22 with the slot 16' and the engagement of the tip 17 in the groove 20. The blades are supported on their backside by contact of the flat portion 19 with the flat face of the integral fingers .13, and they are prevented from dropping out of the bit by the inclined side 27 abutting the inclined faces 15 and 24. The blades are prevented from breaking by having their lower portions abut each other by the action of the lug 25 in contact with the backsides of the adjacent blade. By this construction the blades are securely held in place and are able to resist forces from all directions.

It can be seen that by this invention a drill bit is provided having demountable blades which can be quickly replaced. The sleeve 12 is prevented from moving upwardly by any convenient means. It is only necessary to rotate the sleeve slightly and at the same time move it upwardly to release the blades. One or more blades can then be replaced and locked into place by merely dropping the sleeve into its locked position.

While this invention has been shown in but a limited number of forms, it is obvious to those skilled in the art that it is not so limited, but it is susceptible of various changes and modifications without departing from the spirit and claims of the invention.

I claim:

1. A drill bit comprising a central body member having means for connecting it to a drill rod and having at least one shoulder projecting radially outward from an adjacent portion of said body member, at least one blade adapted to be demountably received by said body member and having on one of its sides a projection, said last mentioned projection extending approximately transverse to the rest of said blade, said shoulder and said projection each having an inclined face juxtaposed and coplanar with each other, and a sleeve axially slidable on said body member and having locking means including an inclined face adapted to cooperate with said faces in abutting relation for securing said blade to said body.

2. A drill bit comprising a central body member having means for connecting it to a "drill rod and having at its lower end at least one generally longitudinally extending finger, a shoulder extending from said body member at the finger thereof and having an inclined face thereon, at least one generally vertically disposed blade adapted to bedemountably received by said body member adjacent the finger thereof and having on one of its sides a projection with an inclined face thereon, said face on said shoulder being juxtaposed and coplanar with said face on said blade, and a sleeve axially slidable on :said body member and having locking means adapted to cooperate with said faces :for securing said blade to said body member.

3. A drill bit according to claim 2 wherein said looking means includes at least one generally longitudinally extending ear having an inclined side adapted to abut both of said faces.

4. A drill bit comprising a central body member having means for connecting it to a drill rod and having a wall portion at its lower end and at least one generally longitudinally extending integral finger, a shoulder extending from said body member at the finger thereof and having an inclined face thereon, at least one generally vertically disposed blade having on its upper portion a pair of parallel spaced-apart legs adapting it to be demoun-tably received by said body member with one leg disposed to one side of said wall portion and the other leg disposed on the other side of said wall portion adjacent the finger thereof and having on one of its sides a projection with an inclined face thereon, said face on said shoulder being juxtaposed and coplanar with said face on said blade, said blade having on the opposite side thereof a groove adapted to receive a tip of said finger, and a sleeve axially slidable on said body member and having locking means adapted to cooperate with said faces for securing said blade to said body member.

5. A drill bit comprising a central tubular body member having means for connecting it to a drill rod and having at its lower end a plurality of equally spaced, generally longitudinally extending, integral fingers, a shoulder extending from said body member at each of said fingers and having an inclined face thereon, said body member having through its wall a radial slot adjacent each of said fingers and forming with said shoulder a blade seat, a plurality of generally vertically disposed blades each having at their upper portion a pair of parallel spaced-apart legs adapt-ing them to straddle said seat for demountably attaching said blades to said body member and each of said blades having on one side thereof an integral projection with an inclined face thereon, each of the faces on said body member being juxtaposed and coplanar with the respective face on each of said blades, each of said blades having on the opposite side thereof a groove adapted to receive a tip of said finger and each of said blades having their lower end portions extending radially toward each other beneath said body member, each of said lower end portions having a laterally angul-arly projecting lug on one side thereof in freely abutting contact with the backside of the adjacent blade, and a sleeve axially slidable on said body member and having a plurality of equally spaced, generally longitudinally extending, integral ears, each ear having an inclined side adapted to abut one of said faces on said body member and the juxtaposed and coplanar face of one of said blades for securing said blade to said body member.

6. A drill bit comprising a central tubular body member having means for connecting it to a drill rod and having at its lower end a plurality of spaced, generally longitudinally extending, integral fingers, a shoulder portion extending from said body member at each of said fingers and having a face thereon, said body member having through its wall a radial slot adjacent each of said fingers and forming with a portion of said shoulder portion a blade seat, a plurality of generally vertically disposed blades each having at their upper portion a pair of parallel spaced-apart legs adapting them to straddle said seat for demountably attaching said blades to said body member and each of said blades having on one side thereof an integral projection with a face thereon, each of said faces on said body member being respectively juxtaposed and coplanar with the respective face on each of said blades, each of said blades having on the opposite side thereof a groove adapted to receive a portion of said finger and each of said blades having their lower portions extending radially toward each other beneath said body member, and a sleeve axially slidable on said body member having a plurality of spaced, generally longitudinally extending, integral ears, each ear having a front side and a rear side thereon, said front side adapted to abut one of said faces on said body member at one of said fingers and the juxtapositioned and coplanar face of one of said blades and the rear side of said ear having a portion thereof abutting a portion of said last mentioned finger whereby said blade is secured to said body member.

References Cited in the file of this patent UNITED STATES PATENTS .1,873,8'14 Brewster Aug. 23, 1932 2,599,854 McMurdy et al. June 10, 1952 2,615,684 Hawthorne Oct. 28, 1952 2,831,657 Hawthorne Apr. 22, 1958 2,978,049 Skidmore et al. Apr. 4, 1961 3,003,570 Roland Oct. 10', 1961 

1. A DRILL BIT COMPRISING A CENTRAL BODY MEMBER HAVING MEANS FOR CONNECTING IT TO A DRILL ROD AND HAVING AT LEAST ONE SHOULDER PROJECTING RADIALLY OUTWARD FROM AN ADJACENT PORTION OF SAID BODY MEMBER, AT LEAST ONE BLADE ADAPTED TO BE DEMOUNTABLY RECEIVED BY SAID BODY MEMBER AND HAVING ON ONE OF ITS SIDES A PROJECTION, SAID LAST MENTIONED PROJECTION EXTENDING APPROXIMATELY TRANSVERSE TO THE REST OF SAID BLADE, SAID SHOULDER AND SAID PROJECTION EACH HAVING AN INCLINED FACE JUXTAPOSED AND COPLANAR WITH EACH OTHER, AND A SLEEVE AXIALLY SLIDABLE ON SAID BODY MEMBER AND HAVING LOCKING MEANS INCLUDING AN INCLINED FACE ADAPTED TO COOPERATE WITH SAID FACES IN ABUTTING RELATION FOR SECURING SAID BLADE TO SAID BODY. 